A backlight is a form of illumination used in liquid crystal displays (LCDs). Because an LCD does not produce its own light, another light source, the “backlight,” illuminates the LCD so that a visible image is produced. LCDs with backlights are used in many electronic user devices, such as flat panel displays, LCD televisions, mobile devices such as cell phones, etc.
Some LCDs use a backlight that gives off a uniform light over its surface, such as an electroluminescent panel (ELP). Other LCDs use multiple light sources to enable localized dimming, such as light emitting diodes (LEDs), or cold or hot cathode fluorescent lamps (CCFLs or HCFLs). Compared to LCDs with a single uniform backlight, well-designed LCDs with local dimming backlights can exhibit higher energy/power efficiencies, better image qualities, and mura-free (defect free) display qualities.